Model-based system engineering, an industrialization path for decommissioning projects by ASSYSTEM

Dismantling projects (dismantling of the high activity tanks of the UP1 plant, treatment of residual sodium from the Rapsodie facility, recovery of bitumen drums from the STEL Marcoule case mates, ...) are complex because of budgets constraints, no return on investment, and characterized by an environment with great uncertainty (NEA OCDE, The decommissioning and dismantling of nuclear facilities, status, approaches, challenges 2020 [1]). This is particularly true for fuel cycle facilities, which are mainly all first-of-a-kind; but it is also valid for commercial NPP (notably on the budget constraints). The main challenges are to (i) conciliate the cost control & risks of uncertainties due to technical subjects, which is the hard skills of the system, and (ii) manage the interfaces between the product owner, engineering, technology provider, operators, & regulators, which is the soft skills of the system. These projects do not progress as much as everyone would like, with a reluctance to move into execution, stuck into several "rounds" of re-engineering studies leading to additional delays and costs. It is necessary to treat the subject as a complex system. The DEMOLOGIST suite is one answer that we implemented to treat these complex projects as systems by deploying a method based on system engineering management of data while developing adapted digital plug-in software to collect, organize and harmonize the data at every stage (archives, regulators requirements, field operations) to feed the method. This is notably the case on a project aiming at studying the best option to deal with sodium management in France.